Nasa helps monitor Great Barrier Reef

WASHINGTON - Nasa satellites that monitor ocean colour and temperature have joined a global effort to study the worrisome bleaching of coral in Australia's Great Barrier Reef.

Coral reefs get bleached when water is too warm, which forces out tiny algae that live in the coral and help it to thrive and give it its vivid colour, Nasa said in a statement. Without these algae, coral can whiten and eventually die.

"Australia's Great Barrier Reef is the largest and most complex system of reefs in the world, and like so many of the coral reefs in the world's oceans, it's in trouble," said oceanographer Gene Carl Feldman of Nasa's Goddard Space Flight Centre outside Washington.

Nasa's Terra and Aqua satellites offer data about ocean surface temperature and colour, available online within three hours of the satellites' pass. Colour is linked to the concentration of chlorophyll in ocean plants, and shows changes in the ocean's biological productivity.

Researcher Scarla Weeks at the University of Queensland, Australia, use the satellite data to observe changes in sea surface temperatures and ocean primary productivity along the Great Barrier Reef and surrounding waters.

"The Great Barrier Reef is an icon, and we just want to know what we can do to save it," said Weeks in the statement.

"Sea surface temperatures over the last five months are actually higher in certain locations now than they were in 2002 when we witnessed the worst bleaching incident to date."

More information and images are available online at

http://www.nasa.gov/centers/goddard/news/topstory/2006/coral-bleach. html.

- REUTERS